I've had to do this to two of our cats that had CKD (both are gone now) and it can be a bit unnerving at first. I'm guessing your vet showed you the proper way to do this? It may take a second person to help you keep Kitty secure. I let them eat supper while they were getting "infused" and it kind of kept them occupied for a bit. If you have a small room you can use, with few distractions and really no place for him to run to that would be helpful.
Also, here is a website for feline CKF that has a LOT of info on it:
Tanya's Comprehensive Guide to Feline Chronic Kidney Disease - Everything You Need to Know to Help Your Cat
Also, make sure that when you pinch the skin up that you get the needle firmly in place (must be sharp) and not just the very tip of it in. If kitty moves around a bit the tip will pop out and then you have to re-stick them. Having a second person helps because they can kind of hold onto the needle and tubing to make sure it doesn't come out while the other person talks to kitty and scritches and monitors the amount of solution dripping. If you get lucky - one person can easily do it, but if your kitty is squirmy and is resisting like yours - two people will probably be needed. Getting those fluids in is vital.
OH....I totally forgot to say HELLO and welcome to the group!!!!
If you aren't able to do it at home - you'll need to have your vet do it in the office. Good luck to you and your kitty.